Wireless telegraph and telephone aerial



P 1931. c. s. FRANKLIN 1,821,936 V WIRELESS TELEGRAPH AND TELEPHONE AERIA L Original FiLed July 31, 1925 INVENTOR (HARLES SAMUEL FRANKLIN 24 /fldama TORNEY Patented Sept. 8 I93l UNITED STATES PATENT OFFICE CHARLES SAMUEL FRANKLIN, OF BUCKI-IURST I-IILL, ENGLAND, ASSIGNOIR, TO RADIO CORPORATION OF AMERICA, A CORPORATION OF DELAWARE WIRELESS TELEGRAPH AND TELEPHONE AERIAL Application filed July 31, 1925, Serial No. 47,232, and in Great Britain August 5, 1924. Renewed May 5, 1930.

This invention relates to wireless telegraph and telephone aerials and more particularly to wireless telegraph and telephone aerials which are long in proportion to the wave length used.

The objectof my invention is to annul or suppress radiation from half wave length sections of an aerial.

Another object of my invention is to obtain greater efficiency in directional propagations of radio oscillations.

A further object of my invention is the employment of means by which alternate half waves are concentrated.

Other objects and advantages of my 1nvention will appear as set forth more fully in the accompanying specification and by reference to the drawings, in which,

Fig. 1 shows the current distribution and polar diagram of a normal aerial one half wave length long. 7

Fig. 2 is a similar view showing the current distribution curve in three sections and polar diagram of a normal aerial one and a half wave lengths long as comprising s1x loops.

Fig. 3 is also a similar view wherein the aerial is shown as being substantially one and a half wave lengths long withthe center portion of the aerial doubled back on itself and the resulting polar diagram.

In these figures, A represents the aerial, B the standing current distribution curve and G the polar diagram. In Fig. 2, it will be seen that the phases of the current as represented by the two end sections of the curve B are similar and in opposition to the phase of the current in the center section. Inthis figure, the polar diagram C consists of six loops, three on each side of the aerial A.

In Fig. 3, the aerial is shown as being loopedback on itself so that the radiation from this loop portion is suppressed. The current distribution B in this aerial is similar to that shown in Fig. 2 but since radiation from the center portion is annulled, the radiation from the two end portions add in a direction at right angles to the aerial, giving a polar diagram approximately as shown i a at C whereby the aerial in consequence is shown to be much more directional than the aerial exhibited in Fig. 1.

It is known that if any aerial, half a wave length long, is excited electrostatically .from one end, there is produced in the aerial a standing wave which has a maximum current value at the middle. Such an aerial radiates best at right angles to the direction of the wire, the polar curve in the plane of the wire being a figure of 8. If the aerial is one wave length long, then the standing wave has current maximum A wave and :4; wave along the wire. As the current in one half of the wire is opposite in phase to the current in the other half, such an aerial does not radiate in the direction at right angles to the wire, but radiates in two directions approximately on each side of this right angle direction, the polar curve in the plane of the wire being four loops with zeros at right angles to the wire and in the direction of the wire. If the wire is one and a half wave lengths long, then the standing Wave has three maxima of current at A, and

1 wave lengths from the end, the phase of the currents at the A and 1% points being the same and opposite to that at the A point, and the polar curve in the plane of the wire has six loops.

In general, if the length of the wire is n half wave lengths, then the polar curve in a plane of the wire will have 2n loops.

According to this invention, I annul or suppress radiation from every alternate half wave length, and so obtain a polar curve in a plane-of the wire, having substantially only two loops which are in the direction at right angles to the wire, and the sharpness of which is dependent on the length of the wire employed. I obtain this result by concentrating alternate half wave length portions of the wire Within a small space, by winding such portions as inductance coils or by doubling such portions back on themselves so that there is practically no radiation from these portions.

The phases of the currents in the remaining portions are then all substantially the same and add their. effects.v in..the direction at right angles totheewire.

An aerial constructed in this manner may also be advantageously employed fdr receiving.

In a modification, .inapla'ce of isdoubling back on themselves, those parts of the aerial from which it is desired -toannul"radiation; I may employ electrical equivalents, such as an inductance coil having sufficient nat-. ural capacity. The eqivalent inserted to replace a the- :doublingrback? of sthe aerialshould=be substantialzly in tune with theirequency employed :and flshouldshave, small. natural radiation compared with. a straight. wirev aerial of, halt wave length.

My invention mayalso be appliedto a plurality of aerials arrangedina line .and.& any desired degree of concentration maybe obtained. in .planes passing; through the cen; ter lines of the aerial system andparal lel to the aerials I Having;thusdescribed my invention, what. I claim. is new -and desi're tosecure.byiLetters Patent is 1. In awirelessvsystem. ior-transmissiona or reception, an santennanelectrically;long; in. comparison with theuwavelengthe1n.- ployed and .means integralwith the-antennas tosuppress lflCllR-tliOIl-i from ralternatei half wave length portions .of-theantenna;

2. In awwireless. system for transmission; or reception,- an antenna 2 for: obtaining; diarectionalefiects -comprisingsuccessive1rad-i-- ating; andnonrradiating- ,portionsof half. wave-length, each of said. non-radiating por- I tions being.loopedbaclnon itself:

3. The method of. obtaining directive; transmission or reception by the use oiiv R111;- antenna long-in comparison with v the waves-v length employed, .Whicln. consistsin sup; pressing or annulling; radiationa-fr.om alters. nate half wave-length' portions --.ofthe; an; tenna.-..

4.. Ina wireless-system for: transmission or reception, an antenna for obtaining.-,'die 'ectional eflects icomprising'q a;- plurality of radiating portions ofsubstantially half; wavelength and a rnon=radiating portion .ot substantially half; wave-length interposed between said radiating portions.

5. In anantennarsysteman.aerialnfor ob;- taining. directional communication. including a pair of directionalfradiatingportions and an intermediate non-radiating, portion arranged to suppress radiation throughout a portion of said aerial equal to an odd multiple of a half wave length for increasing directivity.

6. An antenna comprising a plurality of radiating and a plurality of substantially non-radiating reactances connected alternately in series, each having an electrical length of a half wave.

7. An antenna comprising a plurality of half wave lengthradiating,wireslocated end to .end, .andaiphase changing means connecting said wires in series with a change in phase sufiicient to make the radiation from :said wirescoph'asal.

8. .Anaantenna: comprising: "aapluralityof 0 radiating wires, each a half Wave in electricallength,locatedend to end, and in inductance a half wave in electrical length for conne'cti'ng'two of saidnadiatingwires" in series.

9.:,Anantenna. comprising a..long Wire and apliirality of poorlyradiating ;reactors... each} a.. half .wave. in. electricalilengtkr in.-. sertedin series with the Wires andnsp aced an, electrical half wave apart along theflwirel.

10.:In,,a .radiating,. system. for radiating high. frequency :energy, a pair of 'fradiato'rs. and a non-radiating elementieii'e'ctively,one half. .wave length long, between the radiators for. establishing electrical connection. between the radiators.

11.. In .a.:radiating system;for.. radiating high. frequency energy, a. pain of .i'adiators and a looped non-radiatingelement one-half." Wave length long: vbetween. the .radizttorsfr 10o establishing, electrical connection between. the radiatorsr.

12. In aflgradiating; system. for. radiating, high ..frequency energy, .a pair of frad-iators and means connecting, the. radiators to-, gether at adjacent ends thereof,fcomprising,.

a linear: wire one-half. wave :length@ long looped 'uponitself "soasto be noneradiatnigl 13. .In .a. system utilizing, highlfrequency.

currents, 13,. substantially, straight conductor. 110.

carrying high frequency currents, another. substantially, straight; conductor carrying high frequency currents adjacent thefirst, mentioned conductor; and non-radiating:

element consisting-0fme-Uhapedconductors substantially one-'hala wave lengtlrlongacoine necting-adjacent ?ends .of the rconductors.

14L! In zaisystem zuti lizing 'liigh frequency currents, I a part I carrying: high frequency" 190 currents, another para'carrying -'hig ire-- quency currents",- and" a' connection '-for ;con-: necting" adjacent terminals of the parts 'con= sisting' of a: wire loopediuponitself so that It is in the .fo'rm-of'a U with legs relatively 125..

close together whereby the elementacts as a n0n-radiating phase 'changer...

l5.;'.A-\connectingelement, for use in a sys-.-

tem.- uti1izing. radio frequency currents. for...

connecting; two parts of thesystem together,

and for producing a phase change in currents flowing from one part to the other of substantially 180 degrees, consisting of a Wire substantially one-half wave length long looped upon itself so that it is in the shape of a U having legs relatively close together.

16. In a system utilizing high frequency currents, a part carrying high frequency currents another part carrying high frequency currents, and a connection for con necting adjacent points of the parts consisting of an arrangement in the form of a U having conducting legs relatively close together whereby the arrangement acts as a non-radiating phase changer.

17 A connecting element, for use in a system utilizing high frequency currents, for connecting two parts of the system together and for producing a phase change in currents flowing from one part to the other of substantially 180 degrees, consisting of a U- shaped arrangement having conducting legs close together whereby radiation from the legs is effectively prevented.

18. In a system utilizing high frequency currents, a substantially straight conductor carrying high frequency currents, another substantially straight conductor carrying high frequency currents adjacent the first mentioned conductor, and, a non-radiating high frequency connecting arrangement for connecting adjacent points on said adjacent conductors, said arrangement being in the form of a U and having conducting legs relatively close together whereby radiation from the arrangement is substantially negligible.

19. In a system for transmitting undulatory high frequency electrical energy, a pair of substantially straight wires, and means connecting adjacent points on the wires con sisting of a conductive arrangement in the form of a U having legs close together whereby radiation from said arrangement is substantially negligible.

20. An antenna system for radiating or receiving electromagnetic waves comprising separated linear radiators, each a half wave length long, and arranged coaxially on a straight line, and, a rectangular U-shaped conductor connecting adjacent ends of said radiators.

21. An antenna system comprising a pair of straight wires separated and arranged coaxially, and, a rectangular U-shaped conductor joining adjacent ends of said separated wires.

22. An antenna system comprising a straight wire, a conductor connected to one end of said wire and at right angles thereto, another conductor perpendicular to and connected to the free end of said first mentioned conductor, another wire coaxial with but separated from said first mentioned wire, and a conductor, perpendicular and joining both said last mentioned conductor and one end of said last mentioned wire.

23. An antenna system comprising two straight wires each a half wave length long and arranged coaxially but separated from each other, and, a U-shaped conducting element formed of substantially straight wires,

the free ends of the legs of said U-shaped conductor joining adjacent ends of said separated wires.

CHARLES SAMUEL FRANKLIN. 

